After creating category and saving i'm redirected to a 404 page

After creating a category i’m redirected to a 404 page. Same when I try to edit a quick links URL, as well as save most other settings in the admin area. My permissions are correct and this is a default install of the latest CS-Cart version. What can I check as far as settings on the server to see what could be causing this. I’m clearly able to access my admin.php login move around but can’t save most settings.